RT Journal Article SR Electronic T1 Effects of nabumetone compared with naproxen on platelet aggregation in patients with rheumatoid arthritis JF Annals of the Rheumatic Diseases JO Ann Rheum Dis FD BMJ Publishing Group Ltd and European League Against Rheumatism SP 257 OP 259 DO 10.1136/ard.58.4.257 VO 58 IS 4 A1 Knijff-Dutmer, Ellen A J A1 Martens, Alexander A1 Laar, Mart A F J vd YR 1999 UL http://ard.bmj.com/content/58/4/257.abstract AB OBJECTIVE To test the hypothesis that nabumetone (a partially selective cyclo-oxygenase-(COX)-2 inhibitor) has less effect on platelet aggregation than naproxen (a non-selective COX-inhibitor) in patients with rheumatoid arthritis (RA).METHODS A crossover study in 10 RA patients was performed, using either nabumetone or naproxen for two weeks, and, after a washout period of two weeks, the other drug during another two weeks. Platelet aggregation studies were performed and bleeding time was assessed before and after each treatment period.RESULTS Maximum platelet aggregation induced by epinephrine and by collagen was significantly more reduced after the use of naproxen than of nabumetone; secondary aggregation induced by ADP and epinephrine disappeared more often by naproxen than by nabumetone. Bleeding times were not influenced.CONCLUSION COX dependent platelet aggregation in RA patients seems to be more inhibited by naproxen than by nabumetone. This may be relevant for patients requiring non-steroidal anti-inflammatory drug treatment but who have an increased risk of bleeding as well.